title: Brain activity and medical diagnosis: an EEG study.
abstract: BACKGROUND
  Despite new brain imaging techniques that have improved the study of the underlying processes of human decision-making, to the best of our knowledge, there have been very few studies that have attempted to investigate brain activity during medical diagnostic processing. We investigated brain electroencephalography (EEG) activity associated with diagnostic decision-making in the realm of veterinary medicine using X-rays as a fundamental auxiliary test. EEG signals were analysed using Principal Components (PCA) and Logistic Regression Analysis
  
  
  RESULTS
  The principal component analysis revealed three patterns that accounted for 85% of the total variance in the EEG activity recorded while veterinary doctors read a clinical history, examined an X-ray image pertinent to a medical case, and selected among alternative diagnostic hypotheses. Two of these patterns are proposed to be associated with visual processing and the executive control of the task. The other two patterns are proposed to be related to the reasoning process that occurs during diagnostic decision-making.
  
  
  CONCLUSIONS
  PCA analysis was successful in disclosing the different patterns of brain activity associated with hypothesis triggering and handling (pattern P1); identification uncertainty and prevalence assessment (pattern P3), and hypothesis plausibility calculation (pattern P2); Logistic regression analysis was successful in disclosing the brain activity associated with clinical reasoning success, and together with regression analysis showed that clinical practice reorganizes the neural circuits supporting clinical reasoning.
authors.affiliation: School of Medicine, University of São Paulo and LIM 01-HCMFMUSP, Dr, Arnaldo 455, 01246-903, São Paulo, Brazil. edmassad@usp.br.
authors.forename: Laila Massad
authors.initials: LM
authors.lastname: Ribas
authors.forename: Fábio Theoto
authors.initials: FT
authors.lastname: Rocha
authors.forename: Neli Regina Siqueira
authors.initials: NR
authors.lastname: Ortega
authors.forename: Armando Freitas
authors.initials: AF
authors.lastname: da Rocha
authors.forename: Eduardo
authors.initials: E
authors.lastname: Massad
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D003657:Decision Making / Q000502:physiology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D025341:Principal Component Analysis; D018634:Veterinarians / Q000523:psychology*